Have you checked with S&W/Walther America? It seems odd that they would have the necesary parts of the pistol and not the spare keys, but anything's possible, I guess.

FWIW, I've found that these so-called alternative keys are far more sturdy, and therefore far more reliable, than the Umarex solution to the issue, which always seems flimsy to me and ready to break. But that's just me.

If you are successful in ordering a spare original key, Edtec, be sure to let us know the part number so that we add it to the list. Thanks in advance.